Synthesis and optical properties of ZnO nanowires with a modulated structure

One-dimensional ZnO nanowires with a modulated structure were synthesized on silicon substrates by a vapour transport and condensation method, using a mixture of In and ZnO powders as a precursor. Each nanowire that has a diameter of uniform size consists of alternating stacks of inversion boundaries and an In/Zn-O block along its growth direction. The formation of such modulated nanostructures is attributed to the relaxation of the lattice strain induced by In doping and their atomic structural model is presented on the basis of the high-resolution transmission electron microscopy (HRTEM) results. In photoluminescence measurements, only a broad ultraviolet (UV) emission peak was observed in the range 10K to room temperature. The dynamic process of the UV emission was discussed.